The Blue Stockings, a colored organization of (St. Louis), started for Chicago on Friday last to play their return games with the Uniques, the champion colored club of that section of the country. They were to have played on Saturday, but rain interfered. On Monday they met the Uniques and warmed them handsomely by a score of 12 to 8. On Wednesday the St. Louisans again visited the White Stocking Park and crossed bats with their Chicago rivals. The Uniques took the lead at the start, but...the Blue Legs went to work to catch up. The Uniques, in nine innings, secured seventeen runs. When the Blues, with fourteen runs to their credit, got two men on bases in their half of the last inning, with nobody out the first base man of the Chicago club hid the ball. Another was furnished and the umpire called "play," but the Chicago men, fearing defeat, refused to continue. The umpire was afraid to declare a forfeit, owing to the mob, who stoned the Blue Stocking omnibus as it left the grounds, severely hurting Wm. Mitchell and Wm. Pitts, two of the St. Louis nine. This outrageous conduct will not soon be forgotten by those who treated the Uniques so well when they were in (St. Louis).-St. Louis Globe-Democrat, October 15, 1875
I've actually written about this incident before as Jon David Cash covered the story in Before They Were Cardinals.